Title:Ab Initio Description of p-Shell Hypernuclei

Abstract: We present the first ab initio calculations for p-shell single-Lambda
hypernuclei. For the solution of the many-baryon problem, we develop two
variants of the no-core shell model with explicit $Λ$ and $Σ^+$,
$Σ^0$, $Σ^-$ hyperons including $Λ$-$Σ$ conversion,
optionally supplemented by a similarity renormalization group transformation to
accelerate model-space convergence. In addition to state-of-the-art chiral two-
and three-nucleon interactions, we use leading-order chiral hyperon-nucleon
interactions and a recent meson-exchange hyperon-nucleon interaction. We
validate the approach for s-shell hypernuclei and apply it to p-shell
hypernuclei, in particular to $^7_Λ$Li, $^9_Λ$Be and
$^{13}_Λ$C. We show that the chiral hyperon-nucleon interactions provide
ground-state and excitation energies that agree with experiment within the
cutoff dependence. At the same time we demonstrate that hypernuclear
spectroscopy provides tight constraints on the hyperon-nucleon interactions and
we discuss the impact of induced hyperon-nucleon-nucleon interactions.